As cristine said her maternal family is from Brazil and Tatiana seems to have the country in her heart given the amount of time she passes there. Andrea too seems to be fond of the country. Are their ties to Brazil enough to want their baby to be born there? We don't know... But maybe they are... we'll have to wait and see...

But where the baby will be born? The couple are in Brazil (at least they were yesterday) and what I know is that travels by plane are not allowed after the 7th month of pregnancy. Her maternal family is from Brazil so the baby will be born here or they will travel again, with the chance of the baby being born in the aeroplane!

I would asssume they travel by private plane so they can travel up and including the day the child is born. It is commercial airlines that does not want to be turned into maternity wards.

Cabin pressure can trigger labor, plus airlines don't want to deliver babies so I doubt they are going anywhere.
It makes sense they want the baby to be born in her country.
I guess they flew to Brazil after NYC, one month at least before the due date, early Feb sounds about right.

I've been wondering why we cannot talk about Tatiana's pregnacy? Are there any reasons for that?

You seem to have misunderstood something. The title of this thread is quite clear - it's the place to discuss the information and pics we get about the pregnancy. No one said that talking about her pregnancy was forbidden. It's a general TRF rule that speculations should be avoided, but the discussions you find on the previous pages are fine.